I'm 21 and what have I bloody achieved???

Yeah okay 21 isn't that old but...
I envy those people who create amazing things while they are still teenagers... you know... I'm not talking about those self-conscious over-worked emo creations wrought with anguish/self pity/fanboy song lyrics. I'm talking about stuff that I'm only just feeling like I could maybe do now. Like actually write a piece of critical writing that isn't just for uni or college... or write song lyrics that are self aware but that won't make me cringe in five years.
People like Laura Marling for example make me feel old and a bit stupid... cos she's the age of my teenage younger sister but her debut album comes close to genius at times. The perfect balance of songs based on experience and wonderful storytelling which is folky without being uncool... and gothic (in the strictest sense) without being overindulgent.
I'm trying to think of other examples outside of music but you know what I mean. Some musicians do just find success because of their youthful engery and attractivenesss but it's often shortlived or becomes embarassing.
I conclusion, I suppose I wish I was some kind of child genius or hot housed myself. Well not really. I feel like I haven't changed, I've always been like this, partially I can't really be bothered but mainly I'm terribly afraid. Anyway, I'll check back in in five years and let you know if I've done anything with my life, like written an opera or something.